Electrical controller and recorder



Nov. 6, 1928.

C. H. WILSON ET AL ELECTRICAL CONTROLLER AND RECORDER Filed Aug. 28, 1924 3 Sheets-Sheet ATIORNEY 3 Sheets-Sheet .2

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C. H. WILSON l AL.

ELECTRICAL CONTROLLER AND RECORDER Filed Aug. 28, 1924 Nov. 6, 1928.

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Nov. 6, T928.

C. H. WILSON ET I'L ELECTRICAL CONTROLLER AND RECORDER Fild Aug. 28,' 1924 3 Sheets-Sheet ATTORNEY /I` .OPatented Novi.- 6, 19.28l

UNITED STATES PATENToFFIca.

CHARLES H. WILSON AND CUTHBER'P J. BROWN, OF NORTH PELHAM, NEW YORK.

ELECTRICAL CONTROLLER AND RECORDER.

Appllcation filed August 28, 1924. Serial No.1734,6^71.

The invention relates to an electrical control for therlnlc apparatus, such as electric furnacesor furnaces heated by fuel combustion, and a recorder for showing the opera 5 tion of the control graphically.

Une of the objects of the invention is to rovide a recorder that will record the perormance and sensitivity of the controller so that an inspection of the record will show m When the controller has been and\is operating to increase the temperature o'r to decrease the temperature and may also show when it stands at the desired temperature and is neitherincreasing nor decreasing thel tem- Iv perature of the furnace.

In the best embodiment of the invention, circuits are employed to control the furnace heat supply, such as the fuel supply or electricv heat-ing element, thereby making the furnace reach the desired temperature and restoring the temperature on departure therefrom, and recording means/sare employed for makinrr a separate record for each control circuit, of the number of times each control circuit is actuated and .the duration of the control. The recording means will -showl the shifting of the control impulses from one control circuit to the other the kind of control :circuit energized, i. e. whether' for increasing or decreasing the heat'supply and temperature, and the number and frequency of the imipulses which have been sent. In one form of the invention, means are provided for recording and signaling when the desired telnperature is being maintained. a A stop is provided with means for brin ing it to a midl position when the desire( temperature is reached, the sto controlling the making or breaking of a t ird intermediate signal circuit, if desired, and a recorderfrecords the number of times and the frequencyt-hat the stop reaches and remains at mid-position and the desired temperature has been attained. With such a desired-tem rature posit-ion for the controller, there'wi 1 be three positions for the marking device on the reeordpaper. The impulses may be shifted from the circuit increasing the-furnace temperature to the circuit decreasing it, or vice versa; or Ifrom the circuit increasing the temperature to the desired-temperature circuit, or vice versa; or from the circuit decreasing the temperature to the desired-temperature circuit, -or vice versa.

When no desired-temperature position is e1nployed7two4 alternative positions for t-he marking device on the paper are provided.

The progress of the record paper under the marker causes a line record to be drawn indieating at what period, for how lone and the number of times., the controller has een issuing impulses for increasing or decreasing temperature and when it remains at an intermediate position and the desired-temperature is reached. i

The autographic record willshow whether or not the controller remains in one position continuously operating for increase or decrease' of tem erature by sending out similar impulses and 1f the record shows that the controller is sending out at intervals impulses for reversal of control, the controller is manifestly sensitive and together with the relays or valves isactually and actively controllin the furnace temperature. f

`In accordance with the invention, when a program mechanism is utilized to operate in connection with the controller, the recorder will show a reversal of impulses or pulsations sent out by the controller for the operation of relays or valves for maintaining a furnace temperature in accordance with the rogram Y schedule or predetermined yrate of c lange of Figure-4, is an illustrative diagram showin the circuits of the apparatus.

paratus shown in Figure 1, on line 3-3 of igure 5 is a detailed cross-sectional view of an adjust-able stop, and Y Figure 6, is a plan view of the record strip showin `the record as made by ^the marker shown 1n the upper part of Figure 4.

It will be understood that the-recording means may be utilized with different forms 'rometer may be varied` as nof temperaturemeasuring orternperature indicating apparatus, the' recording means showing a record"whenever the pointer o in- "dicator moves'in response'to a change of current thru the galvanoineter coil as an indica- `tion of temperature change in the .furnace and the respective-control circuitor intermediate circuit is energized. The form of p for example being of the delecting Drr'sonval type such as a straight millivolt pyrgmeter or of the electrical resistance/type or of potentiometric type wherein the pointer deflections indicate out of balance between the volta e generated: in thethermocouple and a stan ard voltage. .Inthe drawings thepotentionetrictype is illustrated. f 2,., Referring now to tliedrawings (see particularly Figure Il), the standard or supply 'current for the potentiometer is supplied from a batter. -1. From one pole of the batf tery the circuit thru the potentiometer is co'inf pleted by wire 2, potentiometer variable resistance slide-wire 3 and returns to the other `pole of. the battery by way of connection 4, fixed standardizing'resistance 5, returnrwire 6 'and adjustable rheostat 7 The' balancing i current Vis supplied.; the thermoco'uple i8, having ahotjuncti nd cold junctions 10, 11." `Lead 12 connects'the thermocouple to adjusting arm 413,v carrying contact brush` 13..and lead 14 connects the couple thru key .l 21 and galvanometer'coil l5 to 't of'slide-wire 3, The adjusting arm 13 may be adjusted so as to set the contact ybrush 13a 'carried by-it, by means of -a nger piece '16 igure 1), carried by its shaft '17, to such 'a v vposition on the slide-wire 3, that the voltage ropgin the slide-.wire betweenl that. endl of the/slide-wire to which the galva'nometer' arl mature 15 is connected and the point where the brush 13a-contacts with the wire, opposes i fand balances the voltage generated inthe '..therinocouple 8 when that voltage is reprei key 21, the amount of current flowing thru I sentative of the desired temperatureintlie. v furnaceA into which the hot thermoco'u'ple 8 is projected, the furnace not unctiong of the `bein shown in the drawings Inthis way 'the esired-temperature to be maintained by the furnace may be varied and established. L-'By mea-11's of the standardpcell 20 andthe l the SlidQ-.wire 3,-' may be standardized in the t. -usiial manner forcalibratingfthe slide-wire "potentiometer slide-Wire- 3. -With .the cur rent standardized thru. the circuit,` the profv portional voltage drop alongtthe slide-wire i 3 iscalibrated to agree with scale 104:, which eother end.

- "nece-sir scale may be graduated in units of voltage or,

preferably, in units of [temperature basedv upony thermoelectric equivalents of thermo- Icouple 8. J

If the temperature of the thermojunction 9 exceeds or falls below the desired predetermined temperature at which the controller scale is set, ,it .'wili no longer exactly balance the voltage drop in the wire of the potentiometer, between the points on the wire -just mentioned and, therefore, as the normal arrangement of the th'ermocouple circuit is such as to connect thel voltage of the thermocouple in opposition to the voltage tapped ed from the wire3, these two opposing voltages being out of balance .there wilLbe a `netcurrent 'owing in one or'tlie'other directiorNzliru the galvanometer armature 15, thus causing deliection of the v'armature 15 and itsboon 19.

In the form vofi electrical controllerillustrated,'means` are provided, separate from` the galvanometer boom, but depending upon the position of `the boom for selecting and.

closing one of three control circuits, which circuits when energized `operate indicators or ,visible or audible' signals, or relays, or

switches or valvesfor altering the current supply in'electric furnaces or for operating the\.fuel,supply'in furnaces heated by fuel combustion.` Means are thus provided for e/stablishinfr the desired temperature to be maintained:

temperature ofthe heating apparatus is above or below the desired temperature. These means willnow be described.

and for energizing vone or the other of the control circuits whenever thel A shaft 22 mounted in the controller casing,

is driven by some form of motor so as to make a predetermined number of revolutions in a given time interval. -An electric motor 23, outside the casing maybe utilized, the motor driving the shaft 22 bymeans of a worm 2li on the inotorshaft, which in turn'drives the worm wheelv 25 on -a' `counter-shaft,

the counter shaft carrying the worm 26,k

which' in turn meshes with the worm wheel '27| on Shaft 28= Th; shaft 2s may" be clutched to. thel Shaft 22 b sliding A@111mb sleeve. '29, 'the slot of w ich cooperates with the pin 30. Shaft' 22 may drive a shaft 31 in a second electric controller for a'second furnace' by'ineans of clutch' sleeve 32 engag.

ing pin 33l `In this way a plurality of controllers may be driven by one motor. The y three electrical control circuits, 34', 35, 36 may control respectively'liglit or audiblev signals or relays or switches or valves for altering the 'current supply in' electric furnaces or relaysA and valves for operating the fuel supply in furnaces heated by fuel combustion, in a well` known manner. When the current flows thru circuit 34, it causes the temperature of the fu`rnace to increase; when current flows thru circuit 36, it causes the temperature of the fur- V nace to decrease, and when thecurren v thru circuit 35, the galvanometer needle is in the correct temperature position and a white, signal light may be actuated to so indicate.

These circuits are-selected and closed by theI cooperation of the galvanometer boom, a stop and a set of switches, the stop'and switches being controlled by a cam on the controller shaft 22, another cam on the controller shaft closing the respective circuits. T he ram 37 on the con- -troller shaft operates twice for each revolution ofthe shaft, a stop arm 38 thru pin 39 and connecting arm 40. The stop arm 38 carries at its outer end an adjustable stop 41, se-

cured to the arm by screws 42. The arm 38 is secured to shaft 43 and rocks with it, being lowered byrgravity and raised by the cam 37.

l When lowered it will assume one of three pof tion and when the button and boom are beneath the end 45 of the arm, the drop or rock of the arm and consequent rocking of shaft 43 will be the least. The anvil 46 forms a support which thru the button 44 arrests the gravity drop of the arm. Meansl are provided whereby the rocking of the shaft 43, will moveI one of three switch contacts 47, 48, 49, in front of a contacter 50, thus permitting' closing either one of the controlling circuits. 34, 35, 36; depending upon the rock of the shaft 43. A cam 51 on controller shaft 22 moves the contactor 50, against the spring contact 47, 48 or 49, as the Acase may be. The contacter 50 is mounted on an arm 52 secured to shaft 53, the

- arm 52 being^rocked by means of a pin 54, eo-

operating with cam 51. Contactor 50 may be locked in its adjusted position on the arm by locknut 55. By thismeans when the lspring contact 47 is rocked in frent of contacter 50 and the latter operated by'cam 5 1 to close the circuit, a current will fiow from battery 55 thru 50,47, wire 56, thru circuit 34, and return by wire 57 to wire 58, back vto the battery. In doing so it will actuate a. recording mechanism which will be described below. In a similar way when switch contact 48 is opposite point 50, current will flow from battery 55', thru 50, contact spring48, wire 59, thru circuit 35 and return to battery by wire 60. lVhen con- Mtact spring 49 is lowered in front of con- 'tactor 50. current will'flow from battery 55 thru50 and 49 and then by vwire 61 thru circuit"36, returningr to the battery by wire 62. Means are thus provided controlled by the temperature of the furnace, which actuates the thermocouple 8, causing it to deflect the galvanometer boom 19 by causing current'to flow thru galvauomet'er armature 15, for stopping one of the switch contacts 47 48, or 49, in front of the contactorv50, and thereby selecting the circuit 34, 35 or 36, which when actuated will indicate or produce theA necessary change in the temperature of the furnace.

In accordanceI with the invention, means are provided for recording the control signals sent thru thecircuits 34, 35 or 36. In theI form of 'the invention, illustrated, a, record is made and preserved each time the contacter 50 is axtuated to-close its circuit, and means are also provided whereby the recorder will show by separate recordwhich of the contact circuits, i. e. which kind of controlling circuit has been energized, the number of times so ener; gized, and for how'long a period. or duration, the controller has been issuing signals for increasing temperature, for decreasing temperature and when the desired temperature isreached. l

The means for recording the signals will now be described. These' means may be varied. In the form of the invention illustrated, the record is made by means of a sepafclosed at conductor 50. An arm 69 is secured to shaft 53, the outer end of thearm carrying an adjustable set screw 70. The screwA 70, when shaft 53 is rockedto close the circuit, presses the arm at 64 and the marker toward the record strip and holds it in contact therewith. A spring 7l attached to arm 64 is providedso that the screw 70 may yieldingly press the marker against the record strip. This v'permits feeding the record strip while the stylus is in contact with the chart paper and the mark is being made.

Means are provided for feeding the record strip intermittently and at each operation of the marker. In the form illustrated, a pawl 72 is pivotally mounted u on the arm 69, the pawl engaging a ratchet 3 mounted upon a shaft carrying the gear 74. The shaft is earried in a bracket 75. Gear 74 meshes withv gear 76, the gear 76, driving a pin wheel which engages holes 77 inthe record strip, thus feeding the strip from spool 78 over a. platen 78a and to a re-rolling spool 79. The feed begins slightly before the marker con- Y tacts with the ipaper, thus spacing apart the record for each impulse, enablingthe number of impulses to be readily ascertained.

Means are provided controlled by the selecting means whereby the recorder will' show which of the control circuits is actuated In the form illustrated, the marking arm 64 is mounted on shaft 43, so that the marker will move transversely across the record strip/in synchronism with the action of the circuit contact spring 47, 48 or 49. The marker will thus l'uu needed, the electrical recor ertakin be shifted into dierent zones and'will make itsseries'of marks on the record strip at one place'w-hen contact 47 is closed by contacter 50, at another place when contacts 48 and 50 are closed, and in ay third place when contacts 491 and 50 are closed. Y

Means may b e provided for. actuating the marker electrically. In the form of the iiivention illustrated, an electrically operated recording mechanism may be utilized and placed- Wherever the recordin mechanisnlis e place of or being used in addition to t e recorder 'heretofore described. The electrical recorder comprises a pivoted marking arm V80, pivoted at-8'1 and carrying the' marking stylus 82 at its movable end arrangedabove the record paper- 83 which is driven by suitable means thru lits perforations 84. 'Mag-l net has its coil in serieswith the circuit 36,

' magnet 86 has its coil in series with the vcircuit 34, and magnet87, has-its coil -in series with the circuit 35; When the circuit 34, 35, or 36 .-is energized by closing the circuit at 50, `the corresponding m et 86, 87 or 85 is energized. This willaw the marker 82 to 'one side. of the record strip if magnet 86fisenergized by attracting armature 88 or tothe other side if magnet 85 is energized by `attracting` armature 88, or the marking point will ept in'a central positionby magnet 8'( attracting armature 89. The stylus will remain 'always' in contact with vthe paper, each magnet making its' separate and distinct record. v

The mechanism heretofore described and illustrated 'makes use of three :circuits for controlling and indicating the furnacetempeinture. When it is not desired to record.

the intermediate or desiredetemperature position, the Astop at the end of arm 38 is adjusted so. as to provide'two stop positions for the galvanometer boom, one position outside of the stop arm .and the other under the stop arm. ,A The swixtch' point 48 may' be disconnected and the intermediate circuit not utilized, if'desired, .i v

When instead .of desiring the furnace temper'ature to be held constant, it is desired to maintaln it at a predetermined progressive orfretrogressivd rate, as in what has ,beenV styled above and is generally known, as pro' 'gram control, the slide-wire brusl arml 13A is -not' manually turned but lis automatically .turnedby the program mechanism. `ln-the form ,shown in the drawings, it is turned from shaft 22 bymeans of a worm wheel 90,

v meshing with worm gear 91 on counter-shaft 92, the shaft carrying a gear 93, meshing with gear 94, on shaft 95. On shaft 95, a program cam96,- is secured and may be positioned thereon-and secured in place by set-screwl'. A'inger button 98 can be used to manually\. adjustthe parts. AThe program cam turns the brush arm 13, by means of a rock-shaft 99, to which an arrn is secured, the arm carrying pin 101l contacting with theperiphvery of the camand being held thereagainst by '96. The temperature indicating dial 104, lmay be left attached 'to the shaft 17 and turn\` with it (see Figure 4) or the dial 105 (see vFigure 1) maybe fixed and a pointer 106 on the shaft 17, may move over'the dial; the

-dial indicates the temperatures attained by' the furnace, under the action of the program cam. By this means the temperature of the .furnace 'may be caused to rise gradually in a vpredetermined interval of time, or schedule, to a definite temperature and to be maintained at this temperaturefor a Yfixed interval, and

the temperature ofthe furnace lowered gradually or qiickly according to schedule.

While the program mechanism is shifting the brush arm A13, thev cams en shaft 22, will repeatedly act andl the'thermocouple 8 whichis vat the .temperature of thefurnace will pro vide an opposing voltage so as to balance the potentiometer voltage and cause the current to' owin the galvanometeriin onedirection of the other,"thus keeping the furnace temlvperature at the point called for by the brush arm, which is actuated by thevv cam and the rack gearing. The shape of the cam corre, spends tothe desired schedule or program of temperature control, With the parts constructed as illustratedin Figure 4, the electric motor may drive the shaft'22 at a 'speedof one revolution per minu te and the program 96 will make one revolution in'about an hourand a half but it will be understood that any desired ratio between A the'speed Vof shaft 22 `and cam 96 may be maintainedby utilizing suitable change speedy gearing between the shaft'22 and the cam. Hav1n'g ,thus describedthe invention and its operation, 1t will be understood that,

changes may be made in the construction for carrying the invention into efect,without departing from. the vprinciple thereof;

What we claim is:

.1. In .an electrical controller having a galyanometer and its boom andimeans providing an increasing and decreasing control for a thermic a paratus, the combination of means separat@ om but controlled bythe galvanometer boom for selecting the controlling means to be energized, means for sending op# eratmg impulses to e'ach .of said controlling lmeans, and means controlled by said selecting means for separately recording the duration'of the increasing control and of the decreasing control.

2. 1n electrical controller for .heating apparatus having a galvanometer and its boom and aplurality of electrical control circuits, one of which provides means for increasing the'heat supply, and anotherprovides means forL decreasing the heat supply, the combination of means separate from but controlled by the galvanometer boom for selecting the control circuit to be energized,

means for sending operating impulses to said control circuits, and means conti'olled by said selecting means for recording the vduration of the energization of the increasing control circuit and for separately recording the duration of the energization of the decreasing con'- trol circuit.

3. In anelectrical controller having a galvanometer and its boom, the combination with thc control circuits, of means separate from the galvanomctcr boom but controlled thereby for selecting the control circuit to be energized, means 'for sending control impulses so as to selectively energize each of said circuits and means controlled by the selecting means for separately recording the kind of control circuit so energized and the number of impulses so sent., r'

.4. In an electrical controller and recorder provided with means including a plurality of circuits for changing the control of another apparatus, said means being controlled by a measurable condition of the other apparatus under control, a separate marking device, and means for moving said markingdevice into dil'e'rent zones in synchronism with said means for changing the control. d 1- 5. In an electrical controller provided with a plurality of means for changing the control of a furnace, said means being controlled by a ,galvanometeig which is controlled b-y the temperature ofthe furnace, a separate marking device and means for shifting said marking device into the desiredv zone in synclironism with selecting the means for changing the conti-ol.

6. In an electrical controller for controlling furnace temperatures, the combination with two cont-rol circuits and a signal circuit of means dependingupon the temperature of the furnace for selecting the control circuit, means for sending control iinp-ulses so as to selectively energize each of said circuits, and means controlled by said selecting means for separately recording the kind of ,circuit so energized and the number of impulses so sent.

7 In an electrical controller for controlling furnace'tempe atures, the combination with the control circuits, of a galvanonieter, means depending on the temperature of the furnace for actuating said galvanometer and itsv boom, separate means controlled by t-lie boom for selecting one of the control circuits, and means controlled by the selecting means for making a separate record of which control circuit is selected, said record showing the number of times the circuit is energized.

8. In an electrical controller for controlling furnace temperatures, the(4 control circuits of a galvanometcr, potentiometer means depending upon the temthe combination with perature of the furnace for actuating said galvanometer and its boom, separate means controlled by the boom foriselecting each one Iof the control circuits and means controlled by the selecting means for separately recording which control circuit is selected and the number of times it is energized.

9. In an electrical controller for controlling furnace temperatures, the combinationwith lthe control circuits of a galvanonieter, potentiometer means depending on the temperature of the furnace for actuating said galvanometer and its boom, means for adjusting the potentiometer so as to vary the desired ten'iperature at which the furnace may be maintained, separate means controlled by theyboom for selecting each one of the control circuits and means controlled by the sclecting means for separately recording which control circuit is selected and the number of times it is energized.

l0. In an electrical controller for controlling furnace teinperatures, the combination with the control circuits, of a plurality of movabley switch contacts one for each circuit,

means controlled by the temperature of the Y furnace for stopping one of the switch contactsin a predeterminedposition, means for intermittently closing the circuitA thru the selected switch contact and means controlled by the moving switch contacts for making a y record eacli time a circuit at the switch contact is closed.

11. In an electrical controller for controlling furnace temperatures, the combination with the control circuits of means depending upon the temperature of the furnace for sending control impulses so as to selectively energize each of said circuits, means for separately recording t-he kind of control circuit so energized and the number of impulses so sent, said means comprising a marking device, a record chart, means 'for shifting the marking device across the chart into separate zones, and means for moving the device toward the chart and means for operating said shifting means and said moving means synchronously with the means for selectively energizing each of said circuits.

l2. In an electrical controller for furnaces, the combination of a pluralityl of circuits for controlling the furnace temperature, a plurality of corresponding control switches, one for each control circuit, means for shifting `the control switches, a recorder, means for shifting the marking device of the recorder, each time the control switches are shifted, and ineans for operating the marking device to make its record each t-iine the circuit is closed thru the selected switch.

13. In an electrical controller having a plurality of circuits for controlling the furnace. temperature, a galvanometer boom, a movlable stop cooperating therewith, a switch contact for each circuit, means for moving lll movement 'of said stop, a recorder, means vfor shifting the marker of said recorder in unison with the movement of said switch contacts,

land means for operating said marker'each time the circuit thru .one of said contacts is y trolled by isaid galvanonieter cooperating closed.'

14. In an electrical controller ,for controlling temperatures, 4the combination with the control circuits of means for selecting the lcircuit tobeenergized, of'means for sending control impulses so as to selectively energize said/circuits, al potentiometer pyrometerhavmg'an adjustable'reslstancearm, program f means for adjusting said resistance arm, ami

means for adjusting said resistance arm, and

'means controlled by said vselectingmeans for making aseparate record of the duration of impulses so sent for each kind of control circuit so energized. r

15.1'In an electrical controller for lconsending control impulses so Aas to selectivelyyen ergize said circuits,A apotentiometer pyrometer having an adjustable resistance arm,

means-controlled by said selecting means for making a separate record of the duration of impulses so sent for each kind of 'controlcir-Y cuit so energized. 16. In an electrical controller for controL' ling furnace temperatures,the combination with the control circuits, of aswitch for each circuit, a galvanometerand stop controlled by vsaid galvanometer cooperating therewith, a

l thermocouple controlling said galvanometer,

a connection between the switches Iand stop so that the selected position of the switch 1s Icontrolled by the position of the stop', a recorder having a marking device and means for feeding a record chart, and means'for intermittently operating said record chart and said marking device each time the circuitis closed thru one of said switches, thereby mak- 4 galvanometer,

' necesi? energized.

ing a separate record for each control circuit 4 17. In electrical controller for oon- .I

switches land stop so that the selected posiconnectionsl between the tion of the switch is controlled by the position of the stop, va recorder having a marking device, and -means for supplying record paper, a rotary shaft, connections between said shaft and said stop and between saidshaft and said marking device, thereby actuating said Stop and said marking device in unison, and therebymakinga separate record-for eachcontrol circuit energized.

18.-*` In an electrical controller the combination with the control circuits of a temperature controlled'galvanometer boom, O f'meaDS separate from said boom-for selecting the control circuit,-m`eans fo'r`sending control vimpulses f ,o-selectively energizesaid circuits, said selecting means Aincluding a three-position Stott whichis adapted to cooperate with said boom .and means controlled by said boom for recording the number of times the stop stopsat mid-position.

19. In .an `electrical temperature controlled'l galvanometer boom,

` controller provided. a 'with 1a plurality of controlling circuits of a. Y

to-be energized, means for sending operating, A

vimpullses to vsaid controlling circuits, and

means controlled by said selecting means for .marking a sepa-rate record for eachkind of controlling circuits actuated bythe impulses.l i

In testimony whereof, we have, signedl our names tethis specilication. .A l r v cHAs. 'HwnIsou CUTHBERT J. BROWN. 

